Maybe - read the spec sheet on the transistor, see what it is rated for, and compare to the current needed by the motors.I'm running out the door now for an appointment, please don't take my lack of responses for the next several hours as intentionallu ignoring you :-).

I suppose you could, the TIP-120 seems to have good enough ratings for it.http://www.learn-c.com/tip120.pdfPay attention to the pinout, make sure you have a resistor between arduino pin and the base pin, a minimum of 220 ohm should be safe. Try that, measure the voltage across and calculate the current out of the arduino (V across the R)/R = current. Find an R that keeps it around 20mA, maybe 30 if your motors aren't going full speed. You can measure it directly if you have a multimeter with a mA setting; put your meter in series with the arduino output and the resister.You might want to put a heatsink on the transistor (bolt a bit of metal to it to help dissipate heat).Not sure what you'd do with 2 motors spinning in unison ...